I think there should be trading but the game is not ready in my opinion. Content is the number one issue and random drops would have to be drastically changed. For example, ghorn drop rate would need to be exclusive to higher level areas ( we dont have such a thing but the crota raid could work). Plus there needs to be a greater of useful items.... There is only about three of them (approximately). Destiny needs for punch to have an enjoyable trading system and the way destiny is designed, i dont think it would be.